Inboard-outboard drive for watercraft

ABSTRACT

A propulsion unit for an inboard-outboard drive of a watercraft having a power source mounted therein which propulsion unit includes a horizontal drive shaft operatively connected to the power source, a vertical drive shaft, a first gear means connecting the vertical drive shaft to the horizontal drive shaft, a horizontal propeller shaft provided with a propeller, a second gear means connecting the propeller shaft to the vertical drive shaft and a universal joint carried by one of the two horizontal shafts and having a center lying on the axis of the vertical drive shaft. The propulsion unit further includes housing means which is disposed outboard of the watercraft and enclosing movable parts, the housing means including a first housing member and a second housing member one of which is associated with the universal joint to be freely rotatable about the axis of the vertical drive shaft for thereby steering the watercraft, and the first housing member supporting at one end said first gear means and at the other end said second gear means whereby a reaction torque produced by the gear means is absorbed by said first casing member.

United States Patent Morimoto 51 July 25, 1972 INBOARD-OUTBOARD DRIVEFOR WATERCRAFT [72] Inventor: Yoshiro Morimoto, Fujisawa, Japan [73]Assignee: Nissan Motor Company, Limited,

, Yokohama, Japan [22] Filed: Feb. 19, 1971 [21] Appl.No.: 116,963

[30] Foreign Application Priority Data Feb. 24, 1970 Japan ..45/l5756[52] U.S.Cl ..115/35 [51] 1nt.Cl. ..B63h1/04,B63h25/42 [58]FieldofSearch ..ll5/35,4l;74/417,607,l5, 74/69 [56] References CitedUNITED STATES PATENTS 2,532,470 12/1950 Wanzer ..ll5/35 2,880,689 4/1959Bokowski 3,521,589 7/1970 Kemp 3,376,842 4/1968 Wynne ..ll5/35 PrimaryExaminer-Milton Buchler Assistant Examiner-Gregory W. O'ConnorAttorney-John Lezdey [57] ABSTRACT A propulsion unit for aninboard-outboard drive of a watercraft having a power source mountedtherein which propulsion unit includes a horizontal drive shaftoperatively connected to the power source, a vertical drive shaft, afirst gear means connecting the vertical drive shaft to the horizontaldrive shaft, a horizontal propeller shaft provided with a propeller, asecond gear means connecting the propeller shaft to the vertical driveshaft and a universal joint carried by one of the two horizontal shaftsand having a center lying on the axis of the vertical drive shaft. Thepropulsion unit further includes housing means which is disposedoutboard of the watercraft and enclosing movable parts, the housingmeans including a first housing member and a second housing member oneof which is associated with the universal joint to be freely rotatableabout the axis of the vertical drive shaft for thereby steering thewatercraft, and the first housing member supporting at one end saidfirst gear means and at the other end said second gear means whereby areaction torque produced by the gear means is absorbed by said firstcasing member.

4 Claims, 4 Drawing Figures I9 I I6 I017 I g 57 r 2 27b [5 Patented Jul25, 1972 BEST AVAILABLE COPY 3,678,879

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3 (@02 \P-i'I IIIUQEEi 3 44 42 32 INVENTOR YOSH/RO MOR BY 12 0 to ATTORNPatented July 25, 1972 I BEST Amman: copy 3,678,879

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v INVENTOR Y SHI'RO MOK/MOTO g AT I 032m! INBOARD-OUTBOARD DRIVE FORWATERCRAFT This invention relates to an improved inboard-outboard drivefor watercraft. A propulsion unit of an inboard-outboard drive iscommonly mounted on the stern transom of the watercraft and driven by aprime mover mounted inboard of the watercraft. In such a drive,provision is made for rotatably supporting the propulsion unit forsteering on a generally vertical axis. Commonly, the propulsion unit isalso rotatable or can be tilted on a generally horizontal axis to clearan underwater obstruction. It is generally an object of this inventionto provide an improved inboard-outboard drive which includes provisionfor both steering and tilting.

According to this invention, there is provided a propulsion unit for awatercraft which propulsion unit comprises a horizontal drive shaftoperatively connected to the prime mover, a vertical drive shaft, firstgear means connecting the vertical drive shaft to the horizontal driveshaft, a horizontal propeller shaft, second gear means connecting thepropeller shaft to the vertical drive shaft and a universal jointcarried by one of the two horizontal shafts and having its center pointlying on the axis of the vertical drive shaft. The propulsion unitfurther includes housing means which is disposed outboard of saidwatercraft and enclosing movable parts, the housing means including afirst housing member and a second housing member one of which isassociated with the universal joint to be freely rotatable about theaxis of the vertical drive shaft for thereby steering the watercraft,and the first housing member supporting at one end said first gear meansand at the other end said second gear means whereby a reaction torquedeveloped by said gear means is absorbed by said first casing member.

IN THE DRAWINGS:

FIG. 1 is a partially sectioned side elevation of an inboardoutboarddrive according to this invention;

FIG. 2 is a partial top plan view of the inboard-outboard drive of FIG.1;

FIG. 3 is an enlarged perspective view of a portion of a steeringarrangement to be incorporated into the inboard-outboard drive shown inFIG. 1; and

FIG. 4 is a plane view ofthe embodiment shown in FIG. 1.

Referring to FIG. 1, there is shown a propulsion unit for aninboard-outboard drive of a watercraft. The propulsion unit comprises ahorizontal drive shaft supported for rotation within a pair of bearings11 and 12 which are mounted on a bracket 13 rigidly secured to a transom14 of watercraft which is designated at 15. The horizontal drive shaft10 is drivably connected through a fly-wheel 16 to a power source (notshown) mounted inboard of the watercraft 15. At 'an intermediate pointof its length the horizontal drive shaft 10 is provided with auniversaljoint 17, through the center of which extends the generallyhorizontal tilt axis of a propulsion unit generally designated by 18, aswill be more fully described hereinafter. The universal joint 17 ispreferably of a synchromesh type but may be replaced by a Cardan joint.The rear end of the horizontal drive shaft 10 extends into a gear casing19 forming a part of a housing means, which will be described in detailhereinafter. The propulsion unit further comprises a first gear meanswhich is shown to include a drive gear 20 carried on the horizontaldrive shaft 10 and a pair of vertically spaced bevel gears 21 and 22meshing with the drive gear one of which is a forward gear and the othera reverse gear. The bevel gears 21 and 22 are supported for freerotation within bearings 23 and 24 on the upper end of a vertical driveshaft 25. Thus, rotation of the drive gear 20 causes rotations of thebevel gears 21 and 22 in opposed directions. A clutch element 26disposed between the bevel gears 21 and 22 is carried by the verticaldrive shaft and is slidable axially thereon to selectively engage thebevel gears 21 and 22 to complete the drive connection between thehorizontal and vertical drive As seen from FIG. 1, the propulsion unitalso comprises a housing means 27 which is disposed outboard of thewatercraft 15. The housing means is supported by a plate member to bediscussed in detail in the generally horizontal tilt axis to accommodatetilt movements of the propulsion unit. The housing means includes afirst housing member 27a and a second housing member 27b, one of whichis associated with a universal joint, as will be described in detail, tobe freely rotatable about the axis of the vertical drive shaft 25 forthereby steering the watercraft. The first housing member 27a includes acylindrical housing portion (not identified) which supports the verticaldrive shaft 25. As shown in FIG. 1, the first housing member 27a isconstructed to support, in addition to the first gear means, a secondgear means so that a reaction torque developed by the rotation of thepropelleris absorbed by the first housing member 27a. The second gearmeans includes a bevel gear 29 supported through a bearing 28 at thelower portion of the cylindrical housing portion of the first housingmember 27a and a bevel gear 30 which is carried on a horizontalpropeller shaft 31. The horizontal propeller shaft 31 is shown tocomprise first and second shaft portions 31a and 31b. The first shaftportion 310 is supported for rotation within a bearing 32 mounted in thelower portion of the first housing member 270 while the second shaftportion 31b is supported by the second housing member 27b.

The second housing member 2712 also includes a cylindrical portion whichis rotatably supported by the cylindrical housing portion of the firsthousing member 270 on a generally vertical axis corresponding to thevertical drive shaft axis 25 for steering control of the propulsion unit18. A pair of vertical spaced bearings 35 and 36 are mounted within thecylindrical portion of the first housing member 27a to provide for freerotation of the second housing member 27b relative to the first housingmember 27a. At the upper end of the second housing member 27b a seal 37is provided to prevent water from entering the interior of the secondhousing member 27b through a clearance 38 between the coaxially disposedcylindrical portions of the housings 27a and 27b. The second housingmember 27b includes a rearwardly extending cylindrical portion 39 inwhich a pair of horizontally spaced bearings 40 and 41 are mounted torotatably support the second shaft portion 31b of the horizontalpropeller shaft 31. A seal 42 is also provided at the outer end of therearwardly extending cylindrical portion 39 to exclude water from theinterior of the propulsion unit housing 33. In the embodiment shown inFIG. 1, the universal joint, designated at 43 is positioned at anintermediate point of the horizontal propeller shaft 31 so that thecenter of the universal joint 43 lies on the extension of the axis ofthe vertical drive shaft 25. This universal joint 43 also is preferablyof a synchromesh type but may be substituted by a Cardan joint. Asuitable propeller 44 is carried on the horizontal propeller shaft 31and is driven by the vertical drive shaft 25 through the universal joint43 and the bevel gears 29 and 30. A rubber blade 45 is shown to besecured to the second housing member 27b 33 for rotation therewith aboutthe axis of the vertical drive shaft 25.

The gear casing 19 is provided on its top with a lug 46 having aneyehole 47 in which a tilt control cable 48 is anchored at its one end.The control cable 48 is wound on a pulley 49 which is rotatablysupported on the transom of the watercraft 15. As seen in FlGs. l and 4,a plate 50 carried on the gear casing 19 has a forwardly extending arm51 mounted to the lowermost portion thereof as at 52. The arm 51 isformed at the fore end thereof with a notch 53 which is engageable on apin 54. The pin 54 is mounted in one or another of openings 55 arrangedin a rearwardly extending portion 56 of the mounting bracket 13,permitting adjustment of the relative angles between the transom 14 andthe generally vertical steering axis. Tilting of the propulsion unit 18may occur upon meeting an obstruction with sufficient force to cause thearm 51 to disengage from the pin 54. It will be noted that the notch 53is so shaped as to provide a cam action to raise the arm 51 when thesecond housing member 27b is urged away from the transom 14. The secondhousing member arm 51 and rotating the pulley 49 so as to roll thecontrol cable 48 therearound.

Another plate 57 is also carried on the second housing member 27b so asto rotate therewith about the cylindrical portion of the first housingmember 27a The plate 57 is provided at the top thereof with an upwardlyextending rod 58 which bends forwardly at its end to form a horizontalportion 59. As is best seen in FIG. 2, the horizontal portion 59 of theupwardly extending rod 58 has an eyehole 60 therein for movablyreceiving the lower end of a lever 61 which is mounted to a generallyhorizontal steering shaft 62 for pivotal movement about a pin 63. Thesteering shaft 62 is supported by suitable means (not shown) forrotation about its axis. Steering is accomplished by manually rotatingthe steering shaft 62 in a clockwise encounter-clockwise direction tocause the lever 61 to swing, thereby rotating the propulsion unit 18about the axis of the vertical drive shaft 25. It will be understoodthat due to the pivotal connection between the lever 61 and the steeringshaft 62 tilting movements of the propulsion unit 18 will not disturbthe steering geometry of the unit.

A modified form of the propulsion unit is schematically illustrated inFIG. 3, wherein like component parts are designated by same numeralsexcept that a prime has been added thereto. In this embodiment the driveconnections between the horizontal drive shaft 10' and the verticaldrive shaft 25' and between the vertical drive shaft 25' and thehorizontal propeller shaft 31' are mounted within a first housing member27'a which in turn is rotatably supported by the casing a second housingmember 27'b. The horizontal drive shaft 10 is shown to include first andsecond shaft portions 10'a and 10'b between which a universal joint 43'is disposed in such a manner that a center therefore intersects theextension of the axis of the vertical drive shaft 25. A reversing device66 comprising a planetary gear system is provided at an intermediateportion of the horizontal drive shaft 10' in place of the reversingdevice comprising a pair of bevel gears 21 and 22 and the clutch 26shown in FIG. 1.

It will now be appreciated that since a plurality of drive connectionsincluding gear' means are supported by a unitary housing member, areaction torque produced by the gear means is absorbed thereby and,therefore, a propulsion unit can be mounted on the watercraft at thecenter thereof.

What is claimed is:

1. A propulsion unit for an inboard-outboard drive of a watercrafthaving a prime mover mounted within said watercraft, comprising ahorizontal drive shaft operatively con nected to said power source andextending rearwardly of said watercraft, a vertical drive shaft, firstgear means disposed between said horizontal and vertical drive shaftsfor establishing drive connection therebetween, a horizontal propellershaft provided with a propeller for driving said watercraft, second gearmeans disposed between said vertical drive shaft and said propellershaft for establishing drive connection therebetween, a universal jointcarried by one of said two horizontal shafts and having its center pointlying on the axis of said vertical drive shaft, and housing meansdisposed outboard of said watercraft and enclosing said shafts, thirdgear means and universal joint, said housing means including a firsthousing member and a second housing member one of which being associatedwith said universal joint so as to be freely rotatable about the axis ofsaid vertical drive shaft for steering said watercraft, and said firsthousing member supporting at one end said first gear means and at theother end said second gear means whereby a reaction torque developed bypropeller rotation is absorbed by said first housing member.

2. A propulsion unit according to claim 1, wherein said first and secondhousing members respectively include cylindrical portions each extendingalong the axis of said vertical drive shaft, said cylindrical portion ofsaid second housing member being disposed on the cylindrical portion ofsaid first housing member, whereby said second housing member is freelyrotatable about the cylindrical portion of said first housing member.

3. A propulsion unit according to claim 2, wherein said propeller shaftincludes first and second shaft portions supported by said first andsecond housing members, respectively, said first and second shaftportions being connected with each other through said universal jointhaving its center point lying on the axis of said vertical drive shaft,and said first housing member being operatively connected to saidwatercraft, whereby said second housing member is freely rotatable aboutthe axis of said vertical drive shaft in association with said universaljoint.

4. A propulsion unit according to claim 1, wherein said propeller shaftis supported by said first housing member and said horizontal driveshaft includes first and second shaft portions which are supported bysaid first and second housing members, respectively, said second housingmember being operatively connected to said watercraft, and said firstand second shaft portions being connected with each other through saiduniversal joint having its center point lying on the

1. A propulsion unit for an inboard-outboard drive of a watercraft having a prime mover mounted within said watercraft, comprising a horizontal drive shaft operatively connected to said power source and extending rearwardly of said watercraft, a vertical drive shaft, first gear means disposed between said horizontal and vertical drive shafts for establishing drive connection therebetween, a horizontal propeller shaft provided with a propeller for driving said watercraft, second gear means disposed between said vertical drive shaft and said propeller shaft for establishing drive connection therebetween, a universal joint carried by one of said two horizontal shafts and having its center point lying on the axis of said vertical drive shaft, and housing means disposed outboard of said watercraft and enclosing said shafts, third gear means and universal joint, said housing means including a first housing member and a second housing member one of which being associated with said universal joint so as to be freely rotatable about the axis of said vertical drive shaft for steering said watercraft, and said first housing member supporting at one end said first gear means and at the other end said second gear means whereby a reaction torque developed by propeller rotation is absorbed by said first housing member.
 2. A propulsion unit according to claim 1, wherein said first and second housing members respectively include cylindrical portions each extending along the axis of said vertical drive shaft, said cylindrical portion of said second housing member being disposed on the cylindrical portion of said first housing member, whereby said second housing member is freely rotatable about the cylindrical portion of said first housing member.
 3. A propulsion unit according to claim 2, wherein said propeller shaft includes first and second shaft portions supported by said first and second housing members, respectively, said first and second shaft portions being connected with each other through said universal joint having its center point lying on the axis of said vertical drive shaft, and said first housing member being operatively connected to said watercraft, whereby said second housing member is freely rotatable about the axis of said vertical drive shaft in association with said universal joint.
 4. A propulsion unit according to claim 1, wherein said propeller shaft is supported by said first housing member and said horizontal drive shaft includes first and second shaft portions which are supported by said first and second housing members, respectively, said second housing member being operatively connected to said watercraft, and said first and second shaft portions being connected with each other through said universal joint having its center point lying on the axis of said vertical drive shaft, whereby said first housing member is freely rotatable about the axis of said vertical drive shaft in association with said universal joint. 